Parts Needed to Swap a Slant with 440

[70 Challenger Lover]

Picked up a 70 Challenger with a three speed and slant combo. If I were to yank the six and put in a 440, I'm trying to figure out what I'd need and what could be reused.

For instance, by keeping the three speed (which are cool transmissions), no shifter, driveshaft, etc. needed.

Obviously need a bell and different torque shaft but I think certain parts like the pushrod going from pedal to torque shaft are unchanged.

Is the fork the same?

I'm assuming the slant has a smaller diameter flywheel so I'll need that plus a new clutch set up.

I'd be using a mid 70s 440 so I believe the water pump inlet is on the opposite side from earlier 440s. My slant is on the passenger side.

I have wiring harnesses and throttle cables but what else am I forgetting?

[dodj]

K member
Rear axle probably not up to the torque delivered by a 440
I don't know if the 3spd can handle a 440?

[anlauto]

K-Frame ?

[70 Challenger Lover]

K member
Rear axle probably not up to the torque delivered by a 440
I don't know if the 3spd can handle a 440?

Forgot to mention, the original 7 1/4" rear has already been upgraded to an 8 3/4" and I also have a v8 K frame ready to drop in.

Wasn't the three speed standard on the big block RT or was that only for 383 motors? In this case, it's a low mileage but otherwise stock mid 70s 440 with low compression and fairly low hp so if it can handle the 335 hp 383, should be okay with this. I see a four speed upgrade coming soon after that but trying to keep it simple.

[70 Challenger Lover]

K-Frame ?

Forgot to mention I have a nice v8 K frame ready to go.

[dodj]

Wasn't the three speed standard on the big block RT or was that only for 383 motors? In this case, it's a low mileage but otherwise stock mid 70s 440 with low compression and fairly low hp so if it can handle the 335 hp 383, should be okay with this. I see a four speed upgrade coming soon after that but trying to keep it simple.

It could be, I was just raising the question because I only remember hearing about the 3 spds behind low hp engines. Another thought, you will need to rework or replace the engine electrical harness. Probably need to lengthen distributor wires, temp sensor and the like. Not hard to do the work yourself or you could buy a pre-made harness but I find those rather pricey for what they are.

[70 Challenger Lover]

Pretty sure I have a spare wire harness I can use. If not, I'd just alter the one that's coming out and going into the trash anyway.

Making a list of what I need, it's the little things that add up. $100 for a fork, $100 for a bell dust cover, etc. The externally balanced flywheel is going to set me back $250. The bell, closer to $450 which is what the running 440 will be.

I'm hoping maybe the fork is the same. It's possible I could alter the torque tube and save another $100 there.

Looking at internet photos, looks like the water pump inlet is pass side so I should be able to use a flex hose for that hook up and reuse the new 22" radiator I put in not long ago.

[EV2RTSE]

Might want to consider heavier torsion bars given the weight difference between a slant and a 440.

[70 Challenger Lover]

Great advice on the torsion bars. I might have a spare set of the 778/779 bars lying around.

[Mr Cuda]

It's going to need a shaker.  Every cloned 440 R/T needs one.

[70 Challenger Lover]

It's going to need a shaker.  Every cloned 440 R/T needs one.

Well it has the two scoop RT hood now so I'll let the next owner make that expensive upgrade!

[erik70rt]

I know I'm in the minority here, but I'd keep the /6!!!!

Having owned one, it got WAY more attention with that little /6 than a 440 car would get any day. 

It's your car, do what you want.   

[70 Challenger Lover]

I know I'm in the minority here, but I'd keep the /6!!!!

Having owned one, it got WAY more attention with that little /6 than a 440 car would get any day. 

It's your car, do what you want.   

They are cool. That's for sure but this six has a cracked exhaust manifold and when I tried removing it, bolts are breaking off in the head. I'm not sinking a ton of money repairing a motor that the next owner is going to toss in the trash.

I picked up the car last year at a good price and I'm almost done fixing the rust. I just wanted to get it back on the road and maybe make a buck while I'm at it to fund my other projects.

Everyone finds the slant quaint. Like hubcaps. But every potential buyer expects you to give them the car for free because it only has a six. Especially the guys who adore them. Throw in a 440 and the selling price goes up dramatically and becomes more appealing to a larger buying pool at the same time. I'm sick of trying to swim upstream on things like flat hoods, hubcaps, 318s, etc. I can't give any of that away and keep having to scrap that kind of stuff. I'll let other guys go that route.

[dodj]

Great advice on the torsion bars. I might have a spare set of the 778/779 bars lying around.

I have a set but shipping from Canada may make the cost prohibitive. I would repay the favour ( I remember you sent me free parts) and only do it for cost of shipping, no charge for the bars.

[70 Challenger Lover]

Great advice on the torsion bars. I might have a spare set of the 778/779 bars lying around.

I have a set but shipping from Canada may make the cost prohibitive. I would repay the favour ( I remember you sent me free parts) and only do it for cost of shipping, no charge for the bars.

That's a heck of an offer and I appreciate it! Let me go through my stash. I'd hate to take anything I can't immediately use and my memory is that I may have an extra set.